Floor carpeting is commonly cut from a large roll, leaving a raw edge subject to fraying and unraveling. The typical solution is to fold a length of binding tape longitudinally over the cut edge, and sew the tape to the carpet edge. An apparatus known as a puller draws the carpet through a sewing mechanism or, in the case of a portable binder, advances the machine along the carpet edge. The puller is typically a roller connected to a drive motor, the roller having longitudinal serrations or teeth to grip the carpet. The binding tape is payed out through a folder which folds it lengthwise and applies the tape to the carpet edge. The sewing mechanism then sews the binding tape to the carpet in a continuous process. Machines to carry out this procedure are known and, heretofore, have been configured in different ways. Some examples of carpet binding machines are seen in the following U.S. patents and catalogs:
Hartwell, U.S. Pat. No. 2,547,821, and Anderson, U.S. Pat. No. 5,209,171, are both sewing machines mounted on a wheeled base, utilizing a puller having a single roller above the carpet.
Similarly, Michelberger, U.S. Pat. No. 4,062,307, shows a sewing machine mounted on a wheeled base, but employs a puller with a single roller below the carpet, and an idler wheel above.
Michelberger, U.S. Pat. No. 5,020,458, discloses a wheeled machine having a puller with a flat, serrated plate moving in an oval path in the manner of a walking foot, below the carpet.
A catalog from Binders Group Inc., of Parma, Ohio, illustrates a carpet binding machine on wheels, model BG-3WP, having a puller with a single roller mounted below the carpet.
A catalog from NC Binding and Equipment Corp., of Newark, N.J.; depicts two portable machines. The model PBS-2A binder uses a single roller type puller mounted above the carpet. The model PBT-2A binder has two separately mounted pullers above the carpet, with separate mounts, drives and clutches.
The above-described machines display shortcomings in securely attaching tape to a carpet edge. Pullers mounted above the carpet provide more traction upon the carpet surface than those mounted below and therefore are more advantageous. Furthermore, the double puller delivers more traction than the single puller. The double puller is more directionally stable, as it does not tend to walk off the edge of the carpet. The NC model PBT-2A binder is thus superior to the other machines described above. A disadvantage of this model is that the two puller rollers are not always synchronized because each roller is controlled by separate clutches and drives. The duplication of parts is expensive, increases the weight of the portable machine, and adds to maintenance. Accordingly, there is a need to provide a portable carpet binder with two pullers for more traction and stability, yet having better synchronization with fewer mounting and driving components.